This invention relates to an injection blow molding of an article having openings at both ends. More particularly, this invention relates to a new and improved method for injection blow molding in which a parison having two open ends is made by injection molding, thereafter, said parison is blown to form a molded article having two openings at both ends.
In the conventional injection blow molding, a bottomed parison is formed by injecting plastic material into a cavity of an injection mold with a core member. Then, the bottomed parison is transferred to a blow molding station with said core member and blowing operation is carried out to form a blow molded article such as a bottomed bottle.
Accordingly, the prior art of the injection blow molding has been suitable for manufacturing containers having bottoms such as bottles, cups and so forth. It has been, however, impossible or almost impossible to form a plastic article having openings at both ends without a bottom such as bellows, lamp chimneys, etc.